Steven Laureys: How I know 'coma man' is conscious

"Powerlessness. Utter powerlessness. At first I was angry, then I learned to live with it."

These are reportedly the words of Belgian man Rom Houben, believed for over 20 years to be in a vegetative state. Houben drew the attention of the global media this week when it emerged that he may have been conscious the whole time. Videos appeared of him typing his thoughts into a touch screen; he was even reported to be writing a book about his experiences.

From the online videos, it looks as if when Rom Houben types, his eyes are closed, he types surprisingly quickly and that his hand is guided by an aide. Can we be sure the words attributed to him are really his?

What is happening now is very regrettable. I feel sorry for Rom and about what some people have written on the net. He knows what people are saying, and one can only try to imagine what he has already been through. He has gone from being ignored for many years and considered vegetative to being recognised as conscious. And now he is again being treated as if "it is impossible, he cannot be a cognitive being". Should I respond to that? I don't want to.

I accept some people may have been insensitive, but could it be possible that he isn't really communicating through the finger-guided touch screen?

I am a scientist, I am a sceptic and I will not accept any communication device if it is not properly tested. But I am not the one who made him communicate with the touch screen, I was just there to help him get rid of the diagnosis of vegetative state. And I don't think one can say, based on videos on the internet, something meaningful about the use of the touch screen.

Did you ever communicate with him in any other way?

He has undergone a very extensive medical and neurological assessment – but as his physician I cannot tell you more. I am in a difficult position: do you want me to put his medical record on the internet, or show the videos we made for his assessment? I don't think you would like it if I put results of your IQ test on the internet.

Can you say what makes you so sure he is conscious?

When I first saw Rom three years ago, he had been diagnosed as being in a vegetative state. We used the Coma Recovery Scale – Revised (PDF), which is a bedside behavioural assessment done in a very standardised way, and which you do repeatedly so as not to miss any signs of consciousness. And he showed minimal signs of consciousness. So we didn't even need fancy scanning methods to change the diagnosis. Then he had a brain scan – and we saw near-normal brain function.

What kind of a brain scan did you do?

He had many scans – but I don't want to go into this. We can limit ourselves to one brain scan, a PET scan, which is very straightforward. It measures the brain energy used by injecting radioactively labelled glucose.

How did this indicate he was conscious – I thought we didn't yet have a signature of consciousness?

You are right, we don't have the neural correlate of consciousness. However, there is a whole literature on the brain's metabolic activity in the vegetative state and on its activity when it is functioning normally.

I know I did not contribute any creativity by copying this article but what I shared with you hope it will stimulate the passive brain cells of ours :)